Field of the Invention
The present invention relates to: a display control device to be loaded on an image processing apparatus such as a multifunction peripheral (MFP) that is also referred to as multifunctional digital machine; a display control method to be implemented by the display control device; a non-transitory computer-readable recording medium having a display control program stored thereon; and an image processing apparatus.
Description of the Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
There has been a known technique, i.e., an image processing apparatus, such as a multifunctional digital machine that is also referred to as multifunction peripheral (MFP), which is provided with a gesture-enabled operation panel. In such an image processing apparatus, a platform starts generating an image data object when a gesture operation is detected and a display application obtains and displays the generated image data object when the gesture operation is finished.
It is seen in some cases of this technique that an image may be displayed in poor quality or may appear blank because of no other image nearby when being enlarged, because the display data object is updated with an image having been displayed previously when a gesture operation, such as a pinch gesture or a slide gesture, is performed. Thus users bother to check the image when performing a gesture operation, having no chance to obtain new information, which is not user-friendly.
To solve this problem, there is a method of obtaining a new image in response to only a little movement of the coordinate of a touch event on the touch panel, which may cause another problem. That is, with this method, the platform may continue transmitting an image to the display application so many times that the screen hardly can be updated in real time in response to a gesture operation.
To further solve this problem, Japanese Unexamined Patent Publication No. 2012-105171 suggests an image processing apparatus including the following: a memory device that stores a low-resolution image, a medium-resolution image, and a high-resolution image; a preview image generator that generates a preview image from the low-resolution image and that displays the preview image; a low-resolution preview image generator that enlarges or reduces the low-resolution image and that displays the enlarged or reduced low-resolution image, in response to a user instruction to enlarge or reduce the displayed preview image; and a medium-resolution preview image generator that generates a medium-resolution image from the high-resolution or low-resolution image depending on the type of a document and that displays the medium-resolution image in replacement of the displayed preview image, in response to a user instruction to enlarge or reduce the displayed preview image.
According to the cited document, the image processing apparatus is allowed to perform the following: enlarging or reducing a low-resolution image while enlarging or reducing a medium-resolution image; displaying the enlarged or reduced low-resolution image as a preview image before finishing enlarging or reducing the medium-resolution image; and replacing the preview image based on the low-resolution image with another preview image based on the medium-resolution image no sooner than finishing enlarging or reducing the medium-resolution image. Thus users can quickly view the result of enlargement or reduction to eventually see another preview image based on the medium-resolution image as a replacement. That is, the image processing apparatus achieves in high-speed processing and displaying a preview image in good quality even after enlargement or reduction.
Meanwhile, in the technique described in Japanese Unexamined Patent Publication No. 2012-105171, the image processing apparatus is required to have generated a low-resolution image and a high-resolution image and to stored them on the memory device before generating a preview image, which makes the memory space of the memory device occupied for a long period. The image processing apparatus is also required to generate a medium-resolution image from a low-resolution image or a high-resolution image and to enlarge or reduce both the low-resolution image and the medium-resolution image in response to a gesture operation, which makes the whole processing complex.
The description herein of advantages and disadvantages of various features, embodiments, methods, and apparatus disclosed in other publications is in no way intended to limit the present invention. Indeed, certain features of the invention may be capable of overcoming certain disadvantages, while still retaining some or all of the features, embodiments, methods, and apparatus disclosed therein.